However, the food manufacturer has managed to overturn the ban after lodging an appeal for an independent review of the decision, which is only accepted if it is established that there was a “substantial flaw” in the initial ruling.

“Following a lobbying effort from Kellogg’s, the ASA has rowed back from their original decision,” said Caroline Cerny of the Obesity Health Alliance, which lodged the original complaint with the ASA. “The original ruling closed a loophole preventing food companies from advertising to children by using characters and music associated with their unhealthy products.

“This is what happens when a large multinational food company uses its legal weight to fight rulings that influence their profits. Sadly, the price is the future health of our children. This is just another example of why we need strong government action to protect children from unhealthy food marketing, starting with a 9pm watershed on junk food adverts on TV.”

While the ASA deemed in the original ruling that the granola product itself was not junk food, it said that the wider content and context of the ad broke the UK advertising code and banned it.

The advert, they say, featured Kellogg’s famous Coco the monkey character and focused on making the cereal “chocolatey” – a hallmark of the wider Coco Pops range, which is deemed to be too sugary to market to children – and not enough on the product being advertised, healthier granola.

Under UK rules, children cannot be targeted with adverts for products that are high in fat, salt and sugar, and licensed characters should not be used to promote such products to them.

In its appeal, Kellogg’s argued that the ad did show the granola product as being clearly differentiated from the core Coco Pops range, and that rules the ASA enforces state that it is fine to use a brand character usually associated with a sugary food to promote a healthy one.

The company also pointed out that its original Coco Pops range has now been reformulated with a 40% reduction in sugar, which means that it is no longer officially classified as a junk food.

Kellogg’s argued that to rule that the ad for the granola product broke junk food rules “would be inconsistent with the government’s objectives on tackling unhealthy eating and discourage advertisers from developing healthier product alternatives”.

Following the independent review, the ASA has now cleared the ad of breaking any UK advertising rules.

“We considered that Coco Pops Granola was the focus of the ad throughout, including through the use of close-up shots of the product and product pack,” said the ASA. “We noted the ad drew attention to the milk ‘turning chocolatey’, a phrase used in ads in relation to Coco Pops original cereal and other [junk food] products in the range. [But] we considered it would be clear to both adult and child viewers that the product being advertised was Coco Pops Granola.”

It is relatively uncommon for the ASA to be forced into overturning a decision like the Kellogg’s case. The last one was last November in a year that the ASA dealt with over 27,000 complaints about more than 19,000 ads.

A spokeswoman for Kellogg’s said: “We felt the original judgment had potential unintended consequences for the industry and the positive intent of the regulations – acting as a disincentive for food companies like us to develop and launch ‘better for you’ alternatives at a time when people are looking to our industry to take action.”